Data show widespread adoption of active surveillance for certain patients with melanoma
Most adults with sentinel lymph node-positive cutaneous melanoma underwent active ultrasound surveillance rather than surgery across academic medical centers in the U.S., Europe and Australia, according to study results published in Cancer.
The real-world outcomes aligned with findings from the Multicenter Selective Lymphadenectomy Trial II (MSLT2) and other studies that showed nodal ultrasound outperformed completion lymph node dissection, researchers noted.
“We coordinated and led this research effort ... to determine how patients included in MSLT2 were being treated and followed in clinic after the trial,” Jonathan S. Zager, MD, FACS, FSSO, chief academic officer, director of regional therapies and chair of the department of oncologic sciences at University of South Florida Morsani College of Medicine and H. Lee Moffitt Cancer Center, told Healio. “The trial changed the way we treated sentinel lymph node-positive adults in that we now follow the overwhelmingly vast majority with active surveillance in the U.S. instead of completing lymph node dissection. Our goal for the real-world post-MSLT2 study is to look at high-volume melanoma centers and see how they embraced the study results and changed their practices.”
The retrospective cohort included 1,154 adults with sentinel lymph node-positive melanoma treated across 21 academic centers between June 2017 and November 2019.
Zager and colleagues used Kaplan-Meier curves and Cox proportional hazard models to assess the impact of active surveillance combined with adjuvant therapy on all-site RFS, isolated nodal RFS, distant metastasis-free survival and disease-specific survival.
Most patients (84%; n = 965; 61% men) underwent active surveillance with nodal ultrasound, whereas 16% (n = 189; 65% men) underwent completion lymph node dissection.
“We expected that the vast majority would have undergone active surveillance of their at-risk nodal basins instead of dissection,” Zager said.
Patients who underwent dissection tended to be younger than those who received active surveillance (mean age, 57 years vs. 59 years) and appeared more likely to have head and neck primary tumors (21% vs. 12%; P < .01), greater Breslow thickness (> 4 mm, 34% vs. 25%), microsatellites (13% vs. 9%; P = .05) and BRAF mutation status (57% vs. 46%; P = .04).
A similar proportion of patients in the active surveillance group (38%) and dissection group (39%) received adjuvant therapy, which for the majority (83%) of these patients consisted of single-agent anti-PD-1 immunotherapy.
Median follow-up was 11 months.
Results showed 220 patients experienced disease recurrence at any site, including 19% of those in the surveillance group and 22% in the dissection group. Isolated nodal recurrence occurred among 6% of patients on active surveillance vs. 4% who underwent dissection. Overall, 24 patients died of melanoma, including 2% of those in the active surveillance group and 4% in the dissection group.
All isolated nodal recurrences were resectable among patients who received adjuvant therapy without prior dissection. Adjuvant therapy appeared to improve all-site RFS (HR = 0.52; 95% CI, 0.47-0.57); however, researchers observed no differences according to adjuvant treatment or nodal management in disease-specific survival and distant metastasis-free survival.
Results of risk-adjusted multivariable analyses showed an association between completion lymph node dissection and improved isolated nodal RFS (HR = 0.36; 95% CI, 0.15-0.88) but not all-site RFS (HR = 0.68; 95% CI, 0.45-1.02).
“Active surveillance has been adopted for most sentinel lymph node-positive patients. At initial assessment, real-world outcomes align with the MSLT2 randomized trial findings, including among recipients of adjuvant therapy,” Zager said. “We have three other papers in submission that are looking at recurrence patterns, adjuvant therapy choices and results.”
The most prominent finding in the study may be the high adoption of active surveillance by patients with primary melanoma and a positive sentinel lymph node across the broad cadre of academic centers, according to an accompanying editorial by Jeffrey E. Gershenwald, MD, researcher in the department of surgical oncology at The University of Texas MD Anderson Cancer Center.
“This relatively rapid evolution in practice patterns was very likely informed by the lack of an observed survival benefit for patients who underwent dissection vs. active surveillance in both [the German Dermatologic Cooperative Oncology Group and MSLT2] clinical trials,” Gershenwald wrote. “The analysis by Broman and colleagues significantly contributes to a still rapidly developing evidence base of patients with melanoma and a positive sentinel lymph node who are followed with active surveillance. It reveals substantial adoption of randomized clinical trial findings that support active surveillance for these patients and, with limited follow-up, suggests that loss of regional basin control is a very uncommon event in this era of effective adjuvant therapy. Ongoing and future studies throughout the global melanoma community will undoubtedly build on these early data and further inform clinical decision-making for patients who have melanoma with a positive sentinel lymph node.”
For more information:
Jonathan S. Zager, MD, FACS, FSSO, can be reached at H. Lee Moffitt Cancer Center, 10920 N. McKinley Drive, Room 4123, Tampa, FL 33612; email: email@example.com.